Bending machine

ABSTRACT

This disclosure involves a machine for the automatic manufacture of wrought metal scrolls in which two sequentially operated ending mandrels are programmed through varying angular rotation, directions of rotation, mandrel sizes and center-to-center distances to produce a wide variety of scroll sizes and shapes. Disclosed is a novel slotted bending head which allows the workpiece to be drawn through one head while being wound on another head. The slotted bending form serves to guide the workpiece as a trap to hold the workpiece while initiating the second scroll formation. Disclosed also is an improved bending head table assembly with a coaxial table raising system. A pneumatic system including controls for automatically controlling and sequencing the operation to produce a complete double ended scroll without handling of the workpiece except loading and unloading.

United States Patent Jasper et a1.

[ 51 Sept. 19,1972

[541 BENDING MACHINE [72] Inventors: Lane Jasper, 165 N. Catalina, Pasadena, Calif. 91106; Joseph L. Brassner, 4538 Conchita Way, Tarzana, Calif. 91356 [22] Filed: April 28, 1970 [211 App]. No.: 32,661

[52] US. Cl. ..72/l46, l40/l04, 72/298 [51] Int. Cl. ..B21c 47/00, B21d 11/14 [58] Field of Search ..72/l46, 147, 298, 305, 308;

[56] References Cited UNITED STATES PATENTS 2,517,436 8/1950 Jones ..140/92 X 2,659,411 11/1953 Bird ..72/146 X 3,225,795 12/1965 Hogan et a1. ..l40/104 3,010,492 11/1961 Ryder et al. ..'....l40/l04 Primary Examiner- Milton S. Mehr Attorney-C. Lauren Maltby [5 7] ABSTRACT This disclosure involves a machine for the automatic manufacture of wrought metal scrolls in which two sequentially operated ending mandrels are programmed through varying angular rotation, directions of rotation, mandrel sizes and center-to-center distances to produce a wide variety of scroll sizes and shapes.

Disclosed is a novel slotted bending head which allows the workpiece to be drawn through one head while being wound on another head. The slotted bending form serves to guide the workpiece as a trap to hold the workpiece while initiating the second scroll formation.

Disclosed also is an improved bending head table assembly with a coaxial table raising system.

A pneumatic system including controls for automatically controlling and sequencing the operation to produce a complete double ended scroll without han dling of the workpiece except loading and unloading.

16 Claims, 18 Drawing Figures PATENTEB 3.691.807

sum 1 or 7 $25 Y FIG. I

Mil/EN TORS LANE JASPER FIG. 3 v JOSEPH 1.. BRASSNER PATENTED EH m2 3.691.807

sumanr? IIIV vewrons LANE JASPER JOSEPH L. BRASSNER PATENTEDSEP 19 I972 sum 3 or 7 INVENTORS LANE JASPER I JOSEPH L. BRASSNER PATENTEDSEPIB m2 3.691.807

SHEET l UF 7 .a WEL 55 f) Lnl 4s FIG. 9

38 38b 39 'im 5 Q I l 57'* K38 FIG.

INVENTORS LANE JASPER JOSEPH L. BRASSNER PATENTEDSEP 19 I972 3.691.807

sum 5 or 7 IN VE N TORS LANE JASPER JOSEPH L. BRASSNER PATENTEI] SEP I 9 I972 SHEET 5 BF 7 8o |O BLEED AIR SHUTTLE FREE 83 92fi VALVE FILTER PB 1 9 J '32 START I q 84 I 85 87 88 A O V 93 ..r-fi

86 SHUT 82 OFF I.- IST TURN I35 I" J 95 BLEED AIR Hu a I02 d |o5 SHUTTLE l 98 VALVE I30 I I I4! I40 t No,2 E

Lv 2 I EXISE' R 3 -CYLINDEE I\I 9.I E"EEDE TABLE I RETRACT 65 BLEED AIR ||3 38 SHUTTLE FREE VALVE I07 AIDS v IIO I26 SHUT OFF -0 W3 BLEED AIR CYLINDER N0. 3 ADVANCING I so A SHUTTLE VALVE CYLINDER I46 I30 I35 I l RETRACT CYLINDER No.5 EXTENDED I I5l 430 fii I36 V A f P82 mvewrons *RESET h I35 LANE JASPER V JOSEPH L. WSSNER SHUT OFF PATENTEDSEPIQ I972 3.691.807

sum 7 or 7 LANE JASPER JOSEPH L. BRASSNER BY This invention relates to the field of metal working machinery, and more particularly, to machines for the bending of metal scrolls.

Wrought metal scrolls are widely used in such fields as furniture and-architectural decoration. Past decades have established a premium value for such scroll work due to the great amount of manual labor involved in making hand wrought iron with crude blacksmiths tools. More modern methods have included poweroperated mandrels whereby a machine operator can insert one end of a workpiece into a mandrel to form one end curve, then take the workpiece out of the machine, turn it around and insert the other end of the workpiece to form the other end of the scroll. The directions of the curves may be changed to produce either a C scroll or an S scroll by merely changing the orientation of the first curve when inserting the workpiece into the machine for the second bend. Making bends of more than a single revolution has always been more complex. A typical operation includes making the first turn by inserting the straight bar of the workpiece into a blind slot at the origin of a spiral on the mandrel, winding one turn about the spiral, and then raising a continuation of the spiral curve on a concentric outer mandrel surrounding the primary mandrel, and completing additional rotation of both the primary mandrel and the outer mandrel to continue making the curve of the scroll.

The primary problem in previous machines is related to manual feeding and manual control of each sequence in the scroll formation, which materially contributes to manufacturing cost, and which is essentially eliminated by the subject invention.

SUMMARY OF THE INVENTION A scroll bending machine is provided having two parallel and laterally spaced bending heads. The first bending head is in a fixed position and includes a rotatably driven spiral bending form having a workpiece-receiving recess at the origin of the spiral, and the second bending head is at a laterally movable distance from the first head and includes a rotatably driven spiral bending form having a workpiece-sliding through a slot across the origin area of the spiral bending form; whereby a metal strap workpiece is positioned in the respective slots in the two heads, is wound into a spiral form by rotation of the first head while the workpiece slides forward in the slot through the second head, and is then wound into a spiral on the other end by rotation of the second head as the second head is pulled towards the first head by the winding tension of the workpiece. The center distance between heads, the direction and degree of rotation of the heads and the shape of the spiral forms are all variable to produce a wide variety of scroll sizes and shapes. Sequential controls and reset means are provided to automate the operation. A novel slotted self-trapping bending head and a combined bending head and table elevation assembly are likewise disclosed.

2 DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of the exterior of the scroll bending machine showing the controls and the working area with an unformed workpiece in place.

FIGS. 2a, 2b, 2c, 2d, and 2e are perspective views of the working heads of the machine in various stages of forming a typical scroll'shape from a straight bar of metal.

FIG. 3 is a plan view of one alternative scroll shape producible by the machine.

FIG. 4 is a simplified perspective view of the working heads of the machine with the associated drives, shown with an unformed workpiece in place.

FIG. 5 is a simplified perspective view of the working heads of the machine with the associated drives, shown after completing the forming operation, with the workpiece in place.

FIG. 6 is a top plan view of the machine with the top surface removed to show the mechanisms.

FIG. 7 is a side elevation view of the first bending head of the machine, as seen at view AA of FIG. 6.

FIG. 8 is a perspective view of the first bending head of the machine with partial sections of outer components cut away to show internal parts.

FIG. 9 is a partial transverse sectional view taken through section BB of FIG. 6, showing the second bending head.

FIG. 10 is a pneumatic schematic diagram illustrating the operation and controls of a preferred means of driving the machine.

FIG. 11 is a fragmentary elevational view of the bending head retarding device of FIGS. 4, 5 and 6.

FIG. 12 is a fragmentary perspective view of the second bending head cylinder of FIG. 6 including scroll length adjustment means.

FIG. 13 is an exploded view of the second bending head assembly of FIG. 6; and

FIG. 14 is a vertical section of the bending form of FIG. 13 taken along line l4-l4.

DESCRIPTION OF THE PREFERRED EMBODIMENT Now refer to FIG. 1 in which the scroll bending machine 10 is shown having scroll configuration controls 11 on a top surface 12 and operating controls 13 positioned above the top surface. A first bending head 14 is in a fixed location within aperture 15, and a second bending head 16 moves laterally within aperture 15 during portions of the forming operations. Bending head 14 supports a generally spiral-shaped bending form 17 having a blind-ended workpiece receiving slot 18 of an appropriate size to hold a workpiece 20 therein at the origin of its spiral curve. Bending head 15 supports a second generally spiral-shaped bending form 21 having a slot slightly larger than the workpiece therethrough across the width of the spiral origin of the form, so that the unformed workpiece 20 is free to slide within slot 22 when it is engaged in slot 18. Bending head 14 further supports an outer multitum mandrel 23 which may be axially moved upwards into planar alignment with bending form 17 to provide a geometric continuation of the spiral shape of form 17. Similarly, bending head 16 also supports an outer multi-turn mandrel 24 which may be axially moved into 3 planar alignment with bending form 21 to provide a geometric continuation of the spiral shape of form 21. The operating parts of the machine are substantially supported by frame 25, and are partially enclosed by .panel 26.

. Now .referlto FIG. 2a which is a simplified perspective view of the start of the forming operation; wherein form 17 is shown supported by shaft 30 and the end of workpiece has been inserted in the blind-ended slot 18, and form 21 is shown supported by shaft 40 and the still unformed workpiece extends through slot 22.

Now refer to FIG. 2b which is a simplified perspective view of the first part of the scroll forming operation;- wherein form .17 has been driven clockwise by shaft to partially form the first curved end on workpiece 20. The length of workpiece 20 locked in slot 18 and partially wrapped around form 17 is provided as the free end of workpiece 20 slides within slot 22 of form 21.

Now refer to FIG. 2c which is a simplified perspective view of the completion of the first bend in a scroll forming operation; wherein form 17 has been driven fully clockwise through the desired bend are by shaft 30 to completely form the first curved end on workpiece 20; The length of workpiece 20 locked in slot 18 and wrapped around form 17 brings the free end of workpiece 20 through slot 22 of form 21 until the end 32 is flush with the spiral surface of form 21. Through the foregoing operations, the center distance of shafts 30-and 40 has not changed and shaft 40 has not been driven in rotation. I

Now refer to FIG. 2d which is asimplified perspective view of the start of the second bend'in a scroll forming operation; wherein shaft 30 holds form 17 in a fixed rotary position after. the first end of workpiece 20 has been formed. Shaft 40 now rotates bending form 21 counterclockwise and with the end 32 of workpiece 20 trapped within slot 22,v the workpiece begins to wrap around the spiralsurface of form 21, and the tension thereby created in workpiece 20 pulls shaft 40 laterally towards shaft 30. z y

Now refer'to FIG. 2e which is a simplified perspective view of the completion of the second bend in a scroll forming operation; wherein form 21 has been driven fully counterclockwise by shafi 40 through the desired bent arc to completely form the second curved end on workpiece 20. The rotation of form 21 has been completed, the lateral movement of shaft 40 is stopped, and release of the driving torques applied to shafts 30 and 40 permits the natural springback of the workpiece to' loosen its engagement in the bending scrolls and permit removal of the finished part from the machine.

Now refer to FIG. 3 which is a plan view of a reversebend scroll which is produced by reversing the direction of the spiral bending form and direction of rotation of the second bending head.

Now refer to FIG. 4 which is a perspective view of a simplified representation of the machine having only the most basic operating components shown in position for the start of a forming cycle. An unformed workpiece 20 is shown in place in the blind slot 18 of the first bending head 14, passing through the slot 22 in the second bending head 16, and oriented in the machine in general accordance with FIG. 1.

Bending head 14 is supported on a shaft 30, which is in turn supported in bearings 31 and 31a mounted in a pedestal 32. Pedestal 32 is rigidly affixed to the main machine frame 33. Shaft 30 is driven in rotation by a gear 34 which is in engagement with rack 35, axially driven by a fluid cylinder 36. Actuation of cylinder 36 will then cause the rotation of the first bending head in direction A, and will start the first operation of the bending cycle in accordance with FIG. 2b and 3c.

The second bending head 16 is supported by shaft 40, which is in turn supported in bearings 41 and 41a mounted in a tailstock 42. Tailstock 42 is slidably mounted on an arm 43. A brake pad 44 is disposed between tailstock 42 and arm 43, and is frictionally engaged against am 43 by the locating and adjusting screw 45. An extension 51 of tailstock 42 supports a trigger 52 which adjustably threads into extension 51. Trigger 52 is in axial alignment with a stop switch 53 mounted to the main machine frame 33.

Now refer to FIG. 5 showing a perspective view of the simplified representation of the machine having the basic components at the end of a forming cycle with the heads and workpiece in accordance with FIG. 2e. The first bending head has completed the first bend by extension of rack 35, turning gear 34, shaft 30 and first bending form 17 to wrap the workpiece 20 first around form 17.

The second bending head has also completed the second bending by activation of cylinder 46, extending rack 55, turning gear 54, shaft 40 and second bending form 21 to wrap the other end of workpiece 20 around bending form 21 as in the operations shown in FIGS. 2d and 2e. As the second bending head accomplishes the second bend in the workpiece, the tension developed in the winding of the workpiece overcomes the restraint of a retarding device 38 and pulls the tailstock 42 along arm 43 until the completion of the bend is signalled by actuation of stop switch 53 by the trigger 52. The signal from stop switch 53 is used to de-energize, all power cylinders, and allow the material springback of the workpiece to release the tension on the heads and allow removal of the finished scroll from the machine.

During the bending operations, the centerline of the workpiece 20 is continuously changing with respect to the axes of rotation of both beriding heads, since the workpiece is being wound around two spiral bending forms of ever increasing radii. Arm 43 is cantelevered from a bearing 56 which pivots about a shaft 57, rigidly affixed to the main machine frame 33 andnormal to the centerline of arm 43. Arm 43 can therefore swing laterally to accommodate the changes in workpiece centerline displacement. This free floating features allows the winding of both scrolls without manual intervention.

Now refer to'FIG. 6 wherein a top plan view of the machine 10 is illustrated with the top surface removed to show the general arrangement of the bending heads and associated mechanisms in an actual production machine configuration. The components are identified with the same part numbers used in the previous figures to most easily correlate the functions of the parts. The bending forms 17 and 21 are shown holding workpiece 20 inserted into the blind slot 18 and then through slot 21, respectively. The first head mandrel 23 is shown surrounding form 17, and the second head outer mandrel 24 is shown surrounding form 21, the outer mandrel having a spiral bending form 56 comprising a geometric extension of the shape of form 21, and having a slot therethrough for the passage of workpiece 20.

A rotationally actuated stop switch 37 is shown adjacent to the first bending head, and a similar stop switch 49 is shown adjacent to the second bending head. A resiliently supported guide roller 57 is provided along the side of workpiece to limit lateral bowing of the workpiece during rotation of the first bending head when the workpiece is not yet under tension.

Now refer to FIG. 7 wherein a side elevation view is shown of the first bending head and associated mechanisms of the machine. In this view, the components are shown as they appear in an actual production machine taken at view AA of FIG. 6, and for functional identification of the components, the part numbers correspond to those performing the same function in the previously described FIGS. 4 and 5. In this view, the bending head 14 is shown supporting bending form 17, and also supporting an outer multi-turn mandrel 23 shown axially movable on head 14 and extended upwards into planar alignment with form 17. Head 14 is supported on shaft 30, which is held by bearings 31 and 31a, in turn mounted in pedestal 32 affixed to the main machine frame 33. Shaft 30 and head 14 are driven in rotation by gear 34 turned by rack 35, axially driven by fluid cylinder 36.

The vertical motion of outer mandrel 23 is imparted by a rod 60 passing through the length of shaft 30 and engaging outer mandrel 23 with a cross-pin 61. Rod 60 is moved by lever 62 which is pivoted on bearing 63 and acts against collar 64. Lever 62 is in turn actuated by extension and retraction of fluid cylinder 65.

Bending head 14 is also provided with a cam 66 rotating with head 14 and so shaped as to trip a stop switch 67 at the end of the desired angle of rotation.

Now refer to FIG. 8 wherein a perspective view of the bending head 14 and the outer mandrel is shown. The head 14 has a hollow square cross-section permitting the square shank 69 of form 17 to fit therein and be rotationally driven but subject to easy replacement. Outer mandrel 23 slides axially on head 14, and is comprised of two pieces including a square driving shank 70 and a bending form 71 detachable with screws 72.

Now refer to FIG. 9 wherein a partial transverse section through the machine shows the second bending head and associated mechanisms taken through section BB in FIG. 6. In this view, which shows the cantelevered tailstock support arm 43 and the second bending head'driving rack 55 in cross section, the components are illustrated as they appear in the actual production machine, and for functional identification the part numbers correspond to those performing the same function in the previously described FIGS. 4 and 5.

In this view, bending head 16 is shown supporting bending form 21, and also supporting multi-turn outer mandrel 24, shown axially movable on head 14 and retracted down out of the plane of form 21. Head 16 is supported on shaft 40, which is held by bearings 41 and 41a, in turn mounted in tailstock 42 slidably supported by cantelevered arm 43. Shaft 40 and head 16 are driven in rotation by gear 54 turned by rack 55, axially driven by fluid cylinder 46.

The vertical motion of the outer mandrel 24 is imparted by a rod passing through the length of shaft 40 and engaging outer mandrel 24 with pin 71. Rod 70 is moved by a lever 72 pivoted on bearing 73 and acts against collar 74. Lever 72 is in turn actuated by extension and retraction of fluid cylinder 75.

Bending head 16 is also provided with a cam 76 rotating with head 16 and so shaped as to trip a stop switch 77 at the end of the desired angle of rotation.

Now refer to FIG. 10 which shows a control schematic functional diagram for a preferred embodiment of the invention. A source of fluid pressure 80, preferably air pressure in this embodiment, passes the air through a filter 81 to provide a constant source'of air pressure in line 82, which is monitored by a pressure gauge 83. Line 82 connects to line 84 feeding push-button valve 85. Valve 85 is a latching type valve that remains open after manual actuation until it is closed by a shut-off port 86. Air passing through the opened valve 85 through line 87 through fixed resistance 88 and through line 87a to cylinder 36, and through line 91 to a shuttle valve 92. Pressure on line 91 causes shuttle valve 92 to close off the port receiving line 91, and to open and vent the port receiving line 93 to atmosphere, thereby allowing the bleed air from the moving cylinder 36 to vent through lines 94 and 93, and through shuttle valve 92. a

. Cylinder 36 extends at a rate controlled by resistance 88, and turns the first bending head as shown in F l6. 4, until an actuator 95 is tripped by completion of the first turn of the scroll. Actuator 95 opens valve 96, applying pressure from line 82 through line 97 through ports B and C of three-way valve 100, shown in position for multi-tum bending, to line 98; energizing first bending head outer mandrel cylinder 65, and raising the outer mandrel of the first bending head for multi-turn scroll bending. Flow also moves through line 101 to shuttle valve 102. Pressure on line 101 causes shuttle valve 102 to close line 101, and to open and vent the port receiving line 103, thereby allowing the bleed air fromv the moving cylinder 65 to vent through lines 104 and 103 through the shuttle valve 102.

First bending head cylinder 36 continues to move and complete the second scroll turn and trip actuator 105, mechanically opening valve 106 to connect pressure line 82 through line 110 through resistance 111 and energizing second bending head cylinder 46. Pressure in line 112 causes shuttle valve 113 to close line 112, and to open and vent the port receiving lines 1 l4 and 115, thereby allowing the bleed air from the moving cylinder 46 to vent through the shuttle valve.

Cylinder 46 extends and turns the second bending head as shown in FIG. 4, moving laterally towards the first head overcoming resistance 38 as winding progresses, until actuator 116 is tripped completing the first turn of the second end of the scroll. Actuator 1 16 opens valve 120 applying pressure from line 82 through line 122, through ports A and B of three-way valve 123 to line 124, and through line 125 to the shut-off port of valve 106. Pressure in line 124 passes through line to line 131, which causes shuttle valve 1 13 to vent both ends of cylinder 46; and to line 132, which causes sh uttle valve 92 to vent both ends of cylinder 36; relaxing forces on both bending heads, and freeing the workpiece for removal by the operator.

After removing the workpiece from the machine, the operator manually depresses reset valve 133, causing the pressure from line 82 to pass through line 135 to line l and applying retraction pressure to cylinders 36 and 46, winding the firstand second bending heads and moving the tailstock 42 and second bending head back to the starting position. The machine is thus in condition to receive another workpiece for bending.

The foregoing operating sequence describes the machine as programmed for bending a scroll using multi-turn bending of the first bending head and singleturn bending of the second bending head, as established by the preset positions of the three-way valves 100 and 123. These valves are moved by the scroll configuration controls 11, as shown in FIG. 1. Once these controls are set, the operator uses only the start valve 85 and the reset valve 133, corresponding to operating controls 13 as shown in FIG. 1.

Either of the two bending heads is capable of produc ing single-turn or multi-turn bends, depending on the respective positions of the scroll configuration valves 100 and 123. ,If the valve positions were reversed whereby valve 100 were rotated 90 counterclockwise from the position shown in FIG. 10, and valve 123 were rotated 90 clockwise from the position shown in FIG. 10, the machine would produce a scroll by bending one turn with the first bending head and two turns, including use of the outer mandrel, with the second bending head. This operation is described below:

. The source of fluid pressure 80 passes through air filter 81 to provide a constant source of air pressure in line 82, which is monitored by a pressure gauge 83. Line 82 connects to line 84 feeding push-button valve 85. Valve 85 is pressed and remains open, passing air through line 87 through the fixed resistance 88 to cylinder 36, and through line 91 to shuttle valve 92. Pressure online 91 causes shuttle valve 92 to close off the port receiving line 91, and to open and vent the port receiving line 93 to the atmosphere, thereby allowing the bleed air from the moving cylinder 36 to vent through lines 94 and 93, and through shuttle valve 92.

Cylinder 36 extends at a rate controlled by resistance 88, and turns the first bending head as shown in FIG. 4, until the actuator 95 is tripped by completion of the first turn of the scroll. Actuator 95 opens valve 96, applying pressure from line 82 through line 97 to threeway valve 100. Valve 100 is positioned so that port A aligns with line 97, line 98 is closed ofl to prevent use of the first bending head outer mandrel, and port B is aligned with line 140. The intersecting line 141 carries the pressure back to the shut-off port 86 of start valve 85, closing the valve.

- Pressure from line 97, passing through ports A and B of valve 100 enters line 140, continues through line 142 and thence to line 110, through resistance 111 to second bending head 46. Pressure applied through line 112 to shuttle valve 113 causes valve 113 to close off the port to line 112 and open line 114 to atmosphere, thereby, allowing the bleed air from the moving cylinder 46 through the shuttle valve 113. This starts the second bending head into operation immediately after completion of the singe turn of the first bending head, and as cylinder 46 extends, it turns the second bending head as shown in FIG. 4, moving laterally towards the first bending head until actuator 116 is tripped at the completion of the first turn of the second end of the scroll.

Actuator 116 opens valve 120 applying pressure from line 82 through line 122 to three-way valve 123. Valve 123 is positioned rotated clockwise from the position shown in the diagram of FIG. 10 so that port B is aligned with line 122 and port C is aligned with line 143, and pressure is applied to the second bending head outer mandrel cylinder 75. Pressure is also applied to line 144 to shuttle valve 145, causing valve 145 to close off the port receiving line 144 and to open and vent the port receiving line 146 to atmosphere, thereby allowing the bleed air from the moving cylinder 75 to vent through lines 146 and 147, and through the shuttle valve 75.

Cylinder 75 extends and raises the outer mandrel of the second bending head for multi-turn scroll bending by the second head. No flow is possible through line 125 to shut off valve 106, so cylinder 46 progresses into the second bending turn, continuing to completion of the bend whereat actuator 150 is tripped. Actuator 150 opens valve 151 which applies pressure from line 82 to line 130, line 124 and line 125, shutting off valve 106 at the completion of the extension of cylinder 46, and by pressurization of lines 131 venting cylinders 36 through shuttle valves 92. The bending head 1 is thus relieved of bending torques, the part may be removed and the rest accomplished as previously described.

The foregoing operations have been described for the machine so programmed as to manufacture scrolls with a C configuration, having both ends bent in the same direction. In order to produce scrolls of the S configuration, having the respective ends bent in opposite directions, a reversing valve 152 is disposed in the lines driving the first bending head cylinder 36. For the previously described C, bending valve 152 is positioned with line 87 connected to line 87a, and separately, line 94 connected to line 94a. However, for reverse or S bending, valve 152 is internally positioned reverse the operating directions of cylinder 36 by connecting line 87 to line 94a, and separately,rline 94 to line 87a. This is accomplished by conventional means in accordance with fluid control practices currently known, and the bleed air venting system is unaffected by the change in cylinder direction.

An additional trip lever is however required for both actuator and actuator for the opposite direction of bending head rotation. The duplicate set of levers is omitted rom the drawing in the interest of clarity.

The functions of the components in the described and illustrated preferred embodiment have been kept separated for the purposes of clear explanation of the machines operation. In actual production models, many of the valves are combined in integrated units having short interconnecting ports instead of the long lines illustrated, and including appropriate interlocking shuttles.

The described preferred embodiment shows the use of pneumatic operations for all of the machine functions. It will be immediately apparent to those skilled in the art that the system could function will if the fluid used were a non-compressible hydraulic fluid, as indeed would be a correct selection for a machine to similarly bend very heavy sections. It will also be apparent to those skilled in the art that there is an electrical equivalent for each of the components shown in the schematic diagram of the pneumatic system, and that therefore it would be easily possible to preserve the operating features of the invention and construct a similar machine using electric motors, switches, latching relays and the like. Such variations are clearly within the concept of the invention.

The operating versatility described above is accomplished employing certain features which are shown particularly in FIGS. 11-14.

Referring now to FIG. 1 1, illustrates a head retarding device 38 comprising a spring loaded dog 38a secured by a U shaped clamp 38b with an internal spring biasing (unshown), the dog 38a downward against a latch 39 secured to the tailstock 42. The load applied by the dog 38a is adjustable through spring retaining screw 380. The retarding device is positioned such that the dog 38a engages the latch 39 with the second bending head in the retracted position.

The function of the retarding device 38 is to apply an initial load on the tailstock 42 so that the tailstock remains in place during the winding of the first scroll and not advanced due to sliding friction of the workpiece 20 through the slotted bending form 21. Additionally, and more important, the retarding device 38 restrains the tailstock 42 as the cylinder 46 begins to rotate the second bending head and imparts an initial bend in the workpiece. The workpiece thereafter will advance the tailstock 42 as it shortens under winding. In the absence of a retarding device, the rack 55 may simply advance the entire tailstock without imparting rotation to the second bending head. Other forms of retarding devices such as tension springs may also be used, however, the spring loaded full release device 38 is preferred.

FIG. 12 shows an additional feature which does not appear in detail in the other views. The cylinder 46 of FIGS. 4, 5 and 6 is not permanently fixed to arm 43 but 'is supported on a plate 43a which rides on a channel member 43b. This channel member 43b is secured to the arm 43 of FIGS. 4, 5 and 6. The longitudinal position of the cylinder 46 is adjustable by a screw S whereby the overall length of the scrolls to be formed by the machine may be adjusted. This adjustment allows the same machines to produce scrolls as long as 36 inches and as short as 3 inches in one embodiment.

The configuration of the scrolls whether C or S is likewise easily changed merely by changing the second bending form 21 as shown in FIG. 13. Two mirror image forms are interchangeable merely by lifting the one form as shown from the square opening and replacement. The direction of rotation of the shafts must also be reversed by change of valving as described in connection with FIG. 10.

One further feature of this invention is shown in FIG. 13 and more particularly in FIG. 14. Note in FIG. 13 that the slot 22 of the second bending form 21 does not extend downward to the bottom of the curved body portion. Actually, the slot includes a stop portion 21a best shown in FIG. 14. The workpiece 20 shown in phantom rides over stop 21a in the direction of the arrow during formation of the first scroll end and drops off of the stop 21a into the main slot 22 either by gravity or sprag loading represented by the arrow extending downward. The workpiece is therefore effectively trapped and prevented from backing out of the second winding-head. This feature in addition to the retarding device 38 of FIG. 11 insures precise formation of double ended scrolls by the apparatus in accordance with this invention.

The above-described embodiments of this invention are merely descriptive of its principles and are not to be considered limiting. The scope of this invention instead shall be determined from the scope of the following claims including their equivalents.

We claim:

1. A bending apparatus comprising a first mandrel having a winding head mounted for rotation about an axis;

a second mandrel having a winding head mounted for rotation about an axis generally in parallel relation with the axis of said first winding head;

said winding head on the first mandrel including a holder to receive the end of the work to be wound into a shape;

said second winding head including a slot therethrough positioned to allow the passage of a workpiece through the slot while being wound on the first mandrel;

means for driving the second winding head to produce a second shape, and means for advancing the second winding head toward the first winding head, during the winding of the second shape.

2. The combination is accordance with claim 1 including control means responsive to the completion of the winding of the shape on the first winding head for initiating the driving of the second winding head.

3. The combination in accordance with claim 1 wherein said second winding head includes means for rotating the second winding head during movement of the second winding head toward the first winding head.

4. The combination in accordance with claim 1 including means mounting the second winding head for lateral movement with respect to the direction of feed of the workpiece.

5. The combination in accordance with claim 4 including a frame for mounting the first and second winding heads, an arm pivotly mounded on said frame, said second winding head being mounted on the arm for generally lateral movement of the axis of the second winding head with respect to the axis of the first winding head.

6. A scroll bending machine including a first winding head;

a winding form secured to the first winding head for winding a spiral scroll thereon;

means for driving said first winding head a pre-determined number turns corresponding to the number of turns of the scroll desired;

A second winding head displaced from and positioned in generally parallel axis relationship with the first winding head and including a second winding form;

means for driving the second winding head a predetermined number of turns corresponding to the number of turns desired on the second scroll end;

means for securing a workpiece to be wound into a scroll to the first winding head to commence winding operations;

, ll; said second winding head including an opening therethrough to allow the feed of workpiece through the second winding head during the winding of the first scroll;

control means for actuating the second winding head to wind the second scroll end; said control means being operative in response to the completion of a pre-determined number of turns of the first winding head.

7. The combination in accordance with claim 6 wherein the second winding head includes a slot therethrough positioned to allow the passage of a workpiece therethrough during winding of the first scroll; and

the walls defining the slot spaced to hold the workpiece on winding of the second scroll.

8. The combination in accordance with claim includingmeans for rotating the first and second winding heads and including means responsive to the completion of a predetermined number of turns of the second winding head for releasing drive pressure from the first and second winding heads whereby the completed workpiece may be removed.

9. A table and winding head assembly for bending machine comprising: I

a bending head including an outer winding surface and shank means of non-circular cross section;

a shaft for rotating the winding head including a noncircular axial opening for holding the shank of the winding head;

said shaft including a non-circular outer axially extending shape, an outer mandrel enclosing said shaft in slidable and rotatable engagement therewith, a rod extending into the axial opening of said shaft,

and means coupling said rod to said outer mandrel whereby axial movement of the rod within the shaft produces axial movement of the outer mandrel; and

whereby rotational movement of said shaft produces rotary movement of the winding head.

10. The combination in accordance with claim 9 wherein said winding head isv mounted in slidable, removable engagement with said shaft.

11. The combination in accordance with claim 9 wherein said winding head includes a slot therethrough whereby a workpiece may be passed through the winding head with the outer mandrel is retracted.

12. The combination in accordance with claim 11 wherein the slot in said winding head includes trap means allowing the passage of a workpiece in one direction only.

13. An actuator circuit for a binding machine having a pair of winding heads in generally parallel axis for winding a workpiece therebetween comprising:

drive means for rotating the first of said pair of winding heads;

means responsive to a predetermined number of turns of said first winding head for advancing said second winding head toward said first winding head;

said advancing means comprising fluid actuated means for rotating said second head whereby the winding of a workpiece on said first winding head advances the second winding head toward the first l4i 'i h e rii b ination in accordance with claim 13 wherein said rotating means comprises a pair of actuators and wherein said circuit includes a manual switch means for the application of actuating force to the first actuator and including a limit switch responsive to the pre-determined travel of said first actuator for initiating the operation of the second actuator.

15. The combination in accordance with claim 13 wherein said actuators comprise a pair of cylinders and the actuating force constitutes air pressure.

16. The combination in accordance with claim 13 wherein the combination includes a second switch for resetting said first and second actuators, said second switch being operative to relieve the system of actuating forces whereby at least one winding head is free to turn and the formed workpiece may be removed from the winding heads. 

1. A bending apparatus comprising a first mandrel having a winding head mounted for rotation about an axis; a second mandrel having a winding head mounted for rotation about an axis generally in parallel relation with the axis of said first winding head; said winding head on the first mandrel including a holder to receive the end of the work to be wound into a shape; said second winding head including a slot therethrough positioned to allow the passage of a workpiece through the slot while being wound on the first mandrel; means for driving the second winding head to produce a second shape, and means for advancing the second winding head toward the first winding head, during the winding of the second shape.
 2. The combination is accordance with claim 1 including control means responsive to the completion of the winding of the shape on the first winding head for initiating the driving of the second winding head.
 3. The combination in accordance with claim 1 wherein said second winding head includes means for rotating the second winding head during movement of the second winding head toward the first winding head.
 4. The combination in accordance with claim 1 including means mounting the second winding head for lateral movement with respect to the direction of feed of the workpiece.
 5. The combination in accordance with claim 4 including a frame for mounting the first and second winding heads, an arm pivotly mounded on said frame, said second winding head being mounted on the arm for generally lateral movement of the axis of the second winding head with respect to the axis of the first winding head.
 6. A scroll bending machine including a first winding head; a winding form secured to the first winding head for winding a spiral scroll thereon; means for driving said first winding head a pre-determined number turns corresponding to the number of turns of the scroll desired; A second winding head displaced from and positioned in generally parallel axis relationship with the first winding head and including a second winding form; means for driving the second winding head a pre-determined number of turns corresponding to the number of turns desired on the second scroll end; means for securing a workpiece to be wound into a scroll to the first winding head to commence winding operations; said second winding head including an opening therethrough to allow the feed of workpiece through the second winding head during the winding of the first scroll; control means for actuating the second winding head to wind the second scroll end; said control means being operative in response to the completion of a pre-determined number of turns of the first winding head.
 7. The combination in accordance with claim 6 wherein the second winding head includes a slot therethrough positioned to allow the passage of a workpiece therethrough during winding of the first scroll; and the walls defining the slot spaced to hold the workpiece on winding of the second scroll.
 8. The combination in accordance with claim 5 including means for rotating the first and second winding heads and including means responsive to the completion of a predetermined number of turns of the second winding head for releasing drive pressure from the first and second winding heads whereby the completed workpiece may be removed.
 9. A table and winding head assembly for bending machine comprising: a bending head including an outer winding surface and shank means of non-circular cross section; a shaft for rotating the winding head including a non-circular axial opening for holding the shank of the winding head; said shaft including a non-circular outer axially extending shape, an outer mandrel enclosing said shaft in slidable and rotatable engagement therewith, a rod extending into the axial opening of said shaft, and means coupling said rod to said outer mandrel whereby axial movement of the rod within the shaft producEs axial movement of the outer mandrel; and whereby rotational movement of said shaft produces rotary movement of the winding head.
 10. The combination in accordance with claim 9 wherein said winding head is mounted in slidable, removable engagement with said shaft.
 11. The combination in accordance with claim 9 wherein said winding head includes a slot therethrough whereby a workpiece may be passed through the winding head with the outer mandrel is retracted.
 12. The combination in accordance with claim 11 wherein the slot in said winding head includes trap means allowing the passage of a workpiece in one direction only.
 13. An actuator circuit for a binding machine having a pair of winding heads in generally parallel axis for winding a workpiece therebetween comprising: drive means for rotating the first of said pair of winding heads; means responsive to a pre-determined number of turns of said first winding head for advancing said second winding head toward said first winding head; said advancing means comprising fluid actuated means for rotating said second head whereby the winding of a workpiece on said first winding head advances the second winding head toward the first winding head.
 14. The combination in accordance with claim 13 wherein said rotating means comprises a pair of actuators and wherein said circuit includes a manual switch means for the application of actuating force to the first actuator and including a limit switch responsive to the pre-determined travel of said first actuator for initiating the operation of the second actuator.
 15. The combination in accordance with claim 13 wherein said actuators comprise a pair of cylinders and the actuating force constitutes air pressure.
 16. The combination in accordance with claim 13 wherein the combination includes a second switch for resetting said first and second actuators, said second switch being operative to relieve the system of actuating forces whereby at least one winding head is free to turn and the formed workpiece may be removed from the winding heads. 